Paint-slinger is a phrase used to describe a painter who works diligently and energetically. If you're looking for synonyms to replace this word, there are a variety of options available. For instance, you could use terms such as artist, painter, or even muralist. Alternatively, you might use words such as decorator, colorist, or designer to describe someone who is skilled at painting. You could even use more informal terms such as graffiti artist, tagger, or street artist to describe someone who works in an unconventional manner. Ultimately, the choice of words will depend on context and the tone you wish to convey.